1. Field of the Invention
The present invention relates generally to the charging of batteries and, in particular, to an apparatus and method for identifying batteries of different types and adapting the manner in which such batteries are charged in accordance therewith.
2. Description of Related Art
The use of rechargeable batteries to power electronic devices is well known and desirable in order to minimize cost and maximize use of resources. For example, such batteries have been utilized extensively with handheld mobile telephones and other radio communication equipment among other items. In an effort to maximize the length of time a battery is able to provide adequate power between chargings, several different types of rechargeable batteries have been and are continuing to be developed. This includes batteries made of different materials, such as nickel cadmium, nickel metal hydride, and lithium. Because each type of rechargeable battery has an optimum manner in which it should be charged, it is desirable for a charger to be tailored for each one instead of providing current in the same manner. This requires the charging apparatus to be able to identify the type of battery and provide the charging current in a manner preferred for such battery type.
Several chargers exist for providing charge to batteries of different sizes, shapes, and capacities (e.g., U.S. Pat. No. 5,365,159 to Chen, U.S. Pat. No. 5,357,185 to Chen, U.S. Pat. No. 5,280,229 to Faude et al., U.S. Pat. No. 5,245,266 to Yuen, U.S. Pat. No. 5,157,318 to Wang, U.S. Pat. No. 5,148,094 to Parks et al., U.S. Pat. No. 4,963,812 to Mischenko et al., and U.S. Pat. No. 4,816,735 to Cook et al.). While these chargers appear to be useful for their intended purpose, they do not have the ability to distinguish between batteries of substantially the same size and shape which are made of different materials.
In order to accomplish this task, other charging apparatuses have been disclosed that identify different types of batteries by means of sensing circuits therein which receive certain information from the battery. Examples of this kind of charger are described in U.S. Pat. No. 5,350,993 to Toya et al., U.S. Pat. No. 5,200,686 to Lee, U.S. Pat. No. 5,184,059 to Patino et al., and Japanese Patent 402237439 to Kudo. These chargers tend to overcomplicate the process and therefore increase cost for both the charger and the associated battery.
Although the description of related art has focused on battery chargers and the manner in which they identify batteries of different types, it should be recognized that this is only one area in which battery identification is desirable. Other components (and their functions) in electronic devices oftentimes rely upon or affect the electrical characteristics of a particular battery type, such as circuitry in communication devices relating to transmitter power level and length of transmission. Accordingly, the present invention is concerned with identification of battery types in general, as well as with battery charging devices specifically. In this regard, U.S. Pat. No 5,355,073 to Nguyen and U.S. Pat. No. 4,061,956 to Brown et al. both disclose the broad approach of inserting a tap between cells of a battery for the purpose of monitoring battery voltage as an aid to charging. Neither of these two references, however, specifically recites the use of placing these taps at different points on their batteries for identification purposes.
In light of the foregoing, a primary objective of the present invention is to provide an apparatus having the ability to identify different types of batteries.
Another object of the present invention is to provide an apparatus having the ability to charge different types of rechargeable batteries.
A further object of the present invention is to provide an apparatus having the ability to charge different types of rechargeable batteries according to charging algorithms particularly applicable thereto.
Yet another object of the present invention is to provide an apparatus having the ability to charge rechargeable batteries of different capacities.
Still another object of the present invention is to provide a handheld mobile telephone including an apparatus which is able to identify and charge different types of rechargeable batteries.
Another object of the present invention is to provide a handheld mobile telephone including an apparatus which automatically identifies the type of battery connected thereto.
A further object of the present invention is to provide a battery charger accessory having the ability to identify and charge different types of rechargeable batteries.
An object of the present invention is to provide an interface between a handheld mobile telephone and a battery pack which permits the use of different batteries.
Yet another object of the present invention is to provide an interface between a handheld mobile telephone and a battery pack which automatically identifies the type of battery therein so that it may be charged according to a particular charging algorithm applicable thereto.
Another object of the present invention is to provide a method of identifying the type of battery to be charged and adapting the manner in which the battery is charged in response thereto.
These objects and other features of the present invention will become more readily apparent upon reference to the following description when taken in conjunction with following drawing.
In accordance with one aspect of the present invention, an apparatus for identifying batteries of different types is disclosed. Each battery includes a positive terminal, a negative terminal, and an identification terminal connected to a tap between two cells of the battery. The apparatus includes a positive contact positioned so as to engage the positive terminal of a battery, a negative contact positioned so as to engage the negative terminal of the battery, an identification contact positioned so as to receive a tap voltage from the identification terminal of the battery indicative of a particular battery type, and a microcomputer connected to the positive, negative, and identification contacts, wherein the microcomputer identifies the particular type of the battery on the basis of where the tap voltage lies with respect to a plurality of specified voltage ranges. The apparatus may also include a circuit connected to the microcomputer, the positive contact, the negative contact, and the identification contact for supplying a charging current to the battery in accordance with a specified charging algorithm applicable to the particular battery type.
In accordance with a second aspect of the present invention, a battery pack for a handheld mobile telephone is disclosed as including a housing, a battery having a plurality of cells positioned within the housing, and an interface for electrically coupling the battery to the handheld mobile telephone, wherein the type of battery positioned within the housing is distinguished by a tap voltage provided by the identification terminal. The battery interface further includes a positive terminal connected to the battery at a first end and a negative terminal connected to the battery at a second end, as well as an identification terminal connected to a tap between a pair of cells in the battery.
In a third aspect of the present invention, a handheld mobile telephone is disclosed as including a main housing, a signal processing circuit located within the main housing for operating the handheld mobile telephone in a particular mode of communication, a battery pack attached to the main housing for powering the handheld mobile telephone, an interface for electrically coupling the battery pack with the signal processing circuit, where the interface includes an identification contact for receiving a tap voltage from the battery pack indicative of a particular battery type, and circuitry associated with the signal processing circuit for identifying the particular type of battery pack from the tap voltage. The handheld mobile telephone may also include circuitry associated with the signal processing circuit for charging the battery pack in accordance with a particular charging algorithm applicable to the electrical characteristics of the battery pack.
In accordance with a fourth aspect of the present invention, a method of identifying different types of batteries is disclosed. The method includes the steps of positioning a tap between adjacent cells of each battery, connecting an identification terminal to the tap so that a tap voltage indicative of a particular battery type is provided thereto, electrically coupling the battery to a microcomputer by means of a positive terminal, a negative terminal, and the identification terminal, comparing the tap voltage to a plurality of specified voltage ranges stored in the microcomputer, and identifying the particular type of the battery from the specified voltage range within which the tap voltage lies. The method may also include the step of supplying a charging current to the battery in accordance with a charging algorithm in the microcomputer applicable to the particular battery type.